1. Field of the Invention
This invention relates generally to trailer structures; and, more particularly, to tiltable trailers having an improved tongue retention and release structure.
2. State of the Prior Art
Various structures for trailers that are to be towed behind vehicles are known. One class of trailer structures that have special requirements is the class of trailers that are used to transport various recreational vehicles such as snowmobiles, all terrain vehicles, lawn care equipment, tractors, or the like. Many such vehicles are ground-driven and for ease of loading, it has been found beneficial to provide a trailer bed that tilts. Generally, these trailers are supported on two wheels, are preferably constructed of strong but light weight material, and have a wood bed. Various forms of ramps and tilt beds are known. Trailer beds are alternatively referred to as trailer decks.
Various forms of tilt bed trailers have been disclosed. Such tilt bed trailers have utilized various complex release mechanisms to release the bed from the tongue to allow the bed to rotate and tilt for loading and unloading of vehicles. U.S. Pat. No. 4,222,698 issued to Stuart R. Boelter illustrates a mechanism for adjusting the relative angular position of structures adapted to support a snowmobile. Yet another tilt bed trailer for snowmobiles is described in U.S. Pat. No. 3,885,690 issued to James J. Van and Slambrouck, and illustrates the use of a release lever and detent to free the bed of the trailer to tilt relative to the tongue. U.S. Pat. No. 5,421,612 issued to me described a tilt bed trailer that utilizes a support channel in cooperation with a novel tongue structure to allow the bed supporting frame to tilt. Other types of tilt bed trailers are known in the prior art.
The various structures utilized to retain the tilt bed affixed to a trailer tongue have been found to be relatively complex to manufacture and assemble, in many cases unreliable, and often lacking in ease of use in releasing the bed for tilting.
It has been known in the prior art to construct frame members from bent and formed structural members. The use of steel in fabricating the trailer frames has been shown to be unduly heavy and subject to rusting and corrosion and additional maintenance. More recently it has been known to utilize aluminum in the construction of frame members, and it has been known to utilize extruded aluminum to create predetermined shapes of members that can then be cut to desired length and formed into a trailer frame.
While versatility has been found in the use of extruded aluminum members, there has remained the problem requiring separate types of members for various sizes and capacities of trailers. The construction of prior art trailers has often required the use of precision drilling to allow joining members together or has required welding for structural rigidity. These construction processes do not lend themselves to versatility in use of various members in the positioning and adjustment of location. For example, the structures to mount the axle to the frame has characteristically been fixed for each trailer type and the capacity, and has required different structures to accommodate the mounting. Further, once constructed, such fixed axle mounts do not readily accommodate any adjustments or modifications for differing uses of the trailer.